RESUMO
OBJECTIVE: We sought to estimate the optimal time to deliver uncomplicated monochorionic-diamnionic (MCDA) twins. STUDY DESIGN: Data were retrospectively obtained from twin pregnancies from 2000 through 2009. The gestational week-specific prospective perinatal mortality risk was calculated. A cohort of MCDA twins with nonindicated deliveries was analyzed separately. Neonatal outcomes and costs were compared between MCDA twins with nonindicated deliveries born at specific weeks of gestation, and those born the subsequent week. RESULTS: There were 5894 dichorionic-diamnionic twins and 1704 MCDA twins. After 28 weeks, the gestational week-specific prospective risk of perinatal mortality did not differ between groups. There were 948 MCDA twins with nonindicated deliveries. Until 37 weeks, the risk of severe neonatal morbidity, perinatal mortality, and hospital costs were greater for fetuses delivered compared to fetuses born in a subsequent week. CONCLUSION: To optimize neonatal outcome and decrease hospital costs, MCDA twins should not be delivered <37 weeks unless medically indicated.